sha1_wt.vhd

本算法基于leon2协处理器接口标准

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--
-- Fri Jan  4 15:12:08 2008
--
--      Design name        : sha1
--      Author             : nhm
--      Company            : asic
--
--      Description        : 
--
--
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LIBRARY ieee;
USE ieee.std_logic_1164.all;
USE ieee.std_logic_arith.all;
USE ieee.std_logic_unsigned.all;

ENTITY sha1_Wt IS
   PORT (
      W13_I                 : IN std_logic_vector(31 DOWNTO 0);   
      W8_I                  : IN std_logic_vector(31 DOWNTO 0);   
      W2_I                  : IN std_logic_vector(31 DOWNTO 0);   
      W0_I                  : IN std_logic_vector(31 DOWNTO 0);
      
      COUNTER               : IN std_logic_vector(6  DOWNTO 0);   
      
      CLK                   : IN std_logic;

      WT_O                  : OUT std_logic_vector(31 DOWNTO 0)
          );
END sha1_Wt;

ARCHITECTURE behavioral OF sha1_Wt IS

   SIGNAL SHA1_Wt_1                :  std_logic_vector(31 DOWNTO 0);   
    
BEGIN

   SHA1_Wt_1 <= ((W13_I XOR W8_I) XOR W2_I) XOR W0_I ;

 PROCESS(COUNTER,SHA1_Wt_1,W0_I,W2_I,W8_I,W13_I)
   BEGIN 
         CASE COUNTER IS          --select input data
			   WHEN "0000000" =>
                    WT_O <= W0_I;
			   WHEN "0000001" =>
                    WT_O <= W2_I;
			   WHEN "0000010" =>
                    WT_O <= W8_I;
			   WHEN "0000011" =>
                    WT_O <= W13_I;
            WHEN "0000100" =>
                    WT_O <= W0_I;
            WHEN "0000101" =>
                    WT_O <= W2_I;
            WHEN "0000110" =>
                    WT_O <= W8_I;
            WHEN "0000111" =>
                    WT_O <= W13_I;
            WHEN "0001000" =>
                    WT_O <= W0_I;
            WHEN "0001001" =>
                    WT_O <= W2_I;
            WHEN "0001010" =>
                    WT_O <= W8_I;
            WHEN "0001011" =>
                    WT_O <= W13_I;
            WHEN "0001100" =>
                    WT_O <= W0_I;
            WHEN "0001101" =>
                    WT_O <= W2_I;
            WHEN "0001110" =>
                    WT_O <= W8_I;
            WHEN "0001111" =>
                    WT_O <= W13_I;
            WHEN OTHERS  =>
                    WT_O <= SHA1_Wt_1(30 DOWNTO 0) & SHA1_Wt_1(31);
         END CASE;
 END PROCESS;
   
END  behavioral;